438 research outputs found
Studies in the dinoflagellate genera, Peridinium and Peridiniopsis.
Photoheterotrophy occurs in Peridinium willei, P. limbatum, P. inconspicuum, and Peridiniopsis polonicum. All species tested exhibited photoheterotrophy except P. volzii. Growth of all species was strongly depressed by addition of lactate and propionate; while additions of glucose, glycerol, malonate and sucrose generally enhanced growth. Those species with apical pores (Peridinium limbatum, P. inconspicuum, and Peridiniopsis polonicum) generally demonstrated more pronounced growth enhancement on organic substrates than did species without apical pores. No species demonstrated dark growth on any organic substrate.A technique to stain, squash, and enumerate chromosomes of armored dinoflagellates is presented using a cellulase incubation and propionocarmine stain. Chromosome numbers for six freshwater armored dinoflagellates (Peridinium cinctum, P. inconspicuum, P. limbatum, P. volzii, P. willei, and Peridiniopsis polonicum) range from 41 (p. inconspicuum) to 210 (P. cinctum). Evidence is presented to indicate dinoflagellate aneuploidy in culture.Growth of Peridinium willei, P. volzii, P. cinctum, P. limbatum, and Peridiniopsis polonicum is pH specific while Peridinium inconspicuum shows no pH preference in the range of 5.5-8.5. Growth remained constant for most species tested on ammonium and nitrate from concentrations of 2.94 x 10('-4) to 2.94 mM. Urea and nitrite were universally toxic at 2.94 mM but generally provided growth at lower concentrations. Indeed, urea often provided highest growth rates and was utilized by all six species. Peridiniopsis polonicum could not utilize ammonium or nitrite for growth.Five Peridinium (P. willei Huit.-Kaas, P.volzii Lemm., P. cinctum (O.F.M.) Ehrenberg, P. limbatum (Stokes) Lemm., and P. inconspicuum Lemm.) and one Peridiniopsis (P. polonicum (Wolosz.) Bourrelly) species were tested for auxotrophy, photoheterotrophy, nitrogen source utilization, pH optima, and chromosome numbers. Peridiniopsis polonicum requires vitamin B(, 12), and Peridinium limbatum requires thiamin for growth. Unlike marine Peridinium species, P. willei, P. volzii, P. cinctum, and P. inconspicuum do not display auxotrophy. Peridinium volzii is strongly inhibited by concentrations of biotin above 1 (mu)gL('-1)
Jack Holt Boger Papers - Accession 1517
This collection consists mostly of books collected by Dr. Jack Holt Boger (1922-2008) and the Boger family. Included in the collection is former Winthrop Professor and Administrator (1965-1985), Dr. Jack Boger’s graduate thesis titled, An Inquiry into Life Certification of Teachers and a1973 Citadel yearbook (The Sphinx) that belonged to his son, Thomas Alcott Boger (1951-1976). The collection also consists of journals written by W.W. Hall of Lilly Chapel, Madison County, Ohio from 1892 to 1905. W.W. Hall was related to Jack’s wife (June Durrant Boger, 1920-2013) through her mother Edna Wayne Hall Durrant and was possibly her grandfather. Also, included in the collection is a journal kept by Jack Holt Boger while he served as Lieutenant in the U.S. Navy aboard the U.S.S. Wasatch during WWII from June 27, 1944 through October 20, 1944. There are also several books that were collected by Jack Holt Boger, many of which belonged to his wife’s Durrant Family that range in years from 1841 to 1971.https://digitalcommons.winthrop.edu/manuscriptcollection_findingaids/2565/thumbnail.jp
Holt & Plyler (1984) Checklist of the Vascular Flora of the Robert B. Gordon Natural Area
This research represents the first site-wide floristic survey of the Gordon Natural Area (GNA), and consists of 348 species in 238 genera and 95 families. The survey was conducted by two West Chester University undergraduate students, Jack Holt and Jim Plyler, under the supervision of Dr. William Overlease. The bulk of the work took place during 1984; however, some woody species previously noted in the GNA by Jim Plyler were also incorporated into the list. The checklist was compiled for all vascular families encountered at the GNA, with the exception of the Grass Family (Poaceae), Rush Family (Juncaceae), and Sedge Family (Cyperaceae). This checklist stood as the sole site-wide checklist for the preserve until 2007, when Jack Holt and botanist Janet Ebert conducted the second site-wide survey of the GNA. In contrast to the initial survey, the 2007 survey included grasses, rushes, and sedges. Species names were standardized by N. Ritter to follow the nomenclature in USDA PLANTS. Species marked with an asterisk are those that were last noted in the GNA in 1984. Of the 348 species, 265 are native to the lower 48 States and 81 are introduced (indicated in red in the list). Two species, Calystegium sepens and Polygonum scandens, are considered to be native in some parts of the lower 48 states and introduced in other portions
A Study of the Impact of Walker Lake on the North Branch of Middle Creek Using Metrics Generated by Diatom Biofilm Communities
Middle Creek is a tributary of the main stem of the Susquehanna River, and its watershed is confined mostly to Snyder County. The upper reaches of the stream are defined by two major branches, the North Branch and the West Branch, each of which is interrupted by a reservoir, Walker Lake and Faylor Lake, respectively. Walker Lake is an impoundment of a deep V-shaped valley and is 9-10 meters deep at the dam, which allows it to be stratified in the summer and winter. Summer stratification produces an anoxic hypolimnion, which is drawn off by the bottom outflow dam into the North Branch. During September of 2019 and 2020, the hypolimnion of Walker Lake became anoxic and its outflow below the dam had a strong odor of hydrogen sulfide with deposits of iron (III) oxide-hydroxide covering the cobbles and small boulders. The purpose of this preliminary investigation is to explore the impact of the bottom outflow below the dam and at sample sites downstream before and after fall turnover on the diatom biofilm communities and use them as proxies for the state of the stream. We examined five sites on the North Branch: above the lake (1.5 km above the lake), Walker Lake, below the dam at its outflow, a site 1.2 km downstream called Old Bridge, and a site 3 km from below the dam called Swift Run Confluence. Field measurements, using a YSI 556 multimeter, of pH, conductivity, and % oxygen saturation showed clear impacts when the lake was stratified but began to moderate following fall turnover. The loss of alkalinity and conductivity were particularly noticeable. The alkalinity decreased by 35% between the above site (2,350 µeq/L) and below the dam (1,514.4 µeq). Before turnover, at the below site, biofilm diatoms were scarcely found such that the phytoplankter, Asterionella formosa, which had been flushed from the lake, was the most abundant diatom species encountered from the stones collected at the site. Following turnover, however, the biofilm community reestablished itself and was dominated by Achnanthidium minutissumum in November 2019. Metrics based on diatom community analysis before and after turnover suggest the above lake site was impaired by agriculture (indices indicating high levels of sedimentation and nutrient runoff), but the reservoir did not function as a sediment or nutrient trap. Instead, the downstream sites showed higher impairment than the above lake site
Renewed confidence in the Gospel: The Christological problem of history and revelation in the writings of H R Mackintosh
Abstract not provided
From Personal Data to Digital Legacy: Exploring Conflicts in the Sharing, Security and Privacy of Post-mortem Data
As digital technologies become more prevalent there is a growing awareness of the importance of good security and privacy practices. The tools and techniques used to achieve this are typically designed with the living user in mind, with little consideration of how they should or will perform after the user has died. We report on two workshops carried out with users of password managers to explore their views on the post-mortem sharing, security and privacy of a range of common digital assets. We discuss a post-mortem pri- vacy paradox where users recognise value in planning for their digital legacy, yet avoid actively doing so. Importantly, our find- ings highlight a tension between the use of recommended security tools during life and facilitating appropriate post-mortem access to chosen assets. We offer design recommendations to facilitate and encourage digital legacy planning while promoting good security habits during life
Is there an association between prenatal testosterone and autistic traits in adolescents?
Prenatal testosterone (pT) is a crucial component in physiological masculinization in humans. In line with the Prenatal Sex Steroid Theory of autism, some studies have found a positive correlation between pT and autistic traits in childhood. However, effects in adolescence have not been explored. Hormonal and environmental changes occurring during puberty may alter the strength or the nature of prenatal effects on autistic traits. The current study examines if pT relates to autistic traits in a non-clinical sample of adolescents and young adults (NÂ =Â 97, 170 observations; age 13-21 years old). It also explores pT interactions with pubertal stage and timing. PT concentrations were measured from amniotic fluid extracted in the 2nd trimester of gestation via amniocentesis conducted for clinical purposes. Autistic traits were measured by self- and parent-reports on the Autism Spectrum Quotient (AQ) which provides a total score and 5 sub-scores (social skills, communication, imagination, attention switching and attention to detail). Self-reported pubertal stage was regressed on age to provide a measure of relative timing. We found no statistical evidence for a direct association between pT and autistic traits in this adolescent sample (males, females or full sample). Exploratory analyses suggested that pT correlated positively with autistic traits in adolescents with earlier puberty-onset, but statistical robustness of this finding was limited. Further exploratory post-hoc tests suggested the pT-by-pubertal timing interaction was stronger in males relative to females, in self-reported compared to parent-reported AQ and specifically for social traits. These findings require replication in larger samples. Findings have implications for understanding the effects of pT on human behavior, specifically existence of effects in adolescence
Zika Virus and the Risk for Renter Households
Recent research on family income indicates that a lack of economic stability can affect healthy housing. Those with limited resources experience higher rates of inadequate and unstable housing many times forcing them to live in undesirable communities in which there can be several community-level health-related issues. One community-level health-related factor of concern has been the reemergence of Zika virus. Some research has indicated that a higher risk of catching Zika virus may exist in neighborhoods and areas with unhealthy housing. Therefore, this study sought to explore the existence of a relationship between rental housing and the Zika virus. Our findings indicated a significant correlation existed between renter occupied household units and the presence of Zika virus. This finding is notable as it indicates that renters have a higher chance of contracting Zika virus than non-renters. Future research should further examine the demographic and housing situation in other communities reporting cases of the Zika virus.Population Healt
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